The present invention relates generally to hydraulic brake systems and specifically to pistons of master cylinders for such systems.
Hydraulic brake systems are commonly used on vehicles (e.g., automobiles, snowmobiles, ATVs, motorcycles) to provide a braking function. Such systems typically include a master cylinder designed to be moved by the user (e.g., by a foot pedal or hand lever) to pressurize hydraulic fluid and impart motion to brake pads. Master cylinders commonly include a housing defining a bore, and a piston movable in the bore.
The piston has an outer diameter slightly smaller than the inner diameter of the bore so that the piston can reciprocate within the bore. One or more resilient seals are mounted on the piston to seal the gap between the piston and the bore. The sidewalls of the piston adjacent the seal(s) are called the “lands.”
In some situations, contact can occur between the lands and the bore. Lubrication at this contact point substantially reduces frictional forces in this situation, but it can be appreciated that further reducing resistance between the piston and bore is desired.